PTFE Piston Rings

Polytetrafluoroethylene (PTFE) seals and piston rings have started to replace their carbon counterpart as PTFE seals and rings offer greater durability, have a longer operating life, and can be operated at various pressures, velocities and temperatures.
PTFE seals and rings are becoming more common in a variety of applications and industries because of the unique advantages they offer.
PTFE Piston Rings
PTFE Piston Rings and Guide Rings (Rider rings) for dry-running applications are currently a focal point of technical development. 
They significantly reduce a machine’s operating costs and, in today’s increasingly environmentally aware society, make it easier for operators to fulfill stricter environmental legislation.
Properties
Exceptionally low friction coefficient in combination with metals and plastics
Antiadhesive behavior without any stick-slip effect
High elongation properties enabling easy fitting 
of sealing and guide rings to one-piece pistons
Exceptionally large temperature range from –200°C to +260°C
Chemically resistant to almost all solid, liquid, and gaseous media
Ageing-resistant
Nonflammable
Physiologically neutral in the stated temperature range
Suitable for the Following Application Areas
Compressors operating under full- and low-lube conditions
Gas rotary pumps
Expansion machinery
Liquid gas and vacuum pumps
Rocking piston pumps
Rotary compressors for loading/unloading of silos
Generation of oil-free compressed air for the 
food processing industry, pharmaceutical industry, and dentistry
Compressed air for the craft and do-it-yourself market
Pneumatic hammer drills
Automotive technology, including ride leveling 
and air-conditioning systems